Seminal shock-rocker Alice Cooper, born Vincent Damon Furnier to a lay preacher in Detroit, finally has the fawning film biography he always wanted and maybe even deserved. “Super Duper Alice Cooper,” out Tuesday on demand (and on Blu-ray), salutes the androgy­nous psycho frontman who “drove a stake through the heart of the love generation,” as he once put it.

Definitive though it may be, the documentary fails to note that the man who sang “I’m Eighteen” in 1971 was himself 18 in 1966 — when he would’ve been the perfect age to see how little difference there was between the prophetic B-movie freakshow “Carnival of Souls” and ’60s America. In any case, brilliantly wedding rock ’n’ roll to horror, Cooper — who reportedly modeled his ghastly look on Bette Davis’ wrinkled demon in “What Ever Happened to Baby Jane?” — was simultaneously Jekyll and Hyde, Frankenstein and the monster.

No matter that critic Lester Bangs in proto-Spinal Tap speak, deemed Cooper’s first album a “tragic waste of plastic” — the kids went nuts and Cooper’s bank account bulged. Cooper rocked hard, particularly in commercial terms; the LP that contained the eternally anthemic “School’s Out” sold a million copies in ’72.

But like a lot of things in ’73, Cooper’s luck went limp. After “Muscle of Love,” he dispensed with his bandmates and took up the bottle; not for nothing is his 1976 platter called “Alice Cooper Goes to Hell.” Alas, the rock star’s boozy period nearly stops “Super Duper” dead in its tracks, as well, the movie resorting to a standard-issue recovery narrative that kills much of its buzz.

Still, the film has plenty to recommend, especially in its propulsive first half, whose psychedelic swirl of images is enough to make even a Cooper connoisseur feel woozy. The doc pulls apart the so-called chicken incident of ’69 with less than surgical precision, as it should be, and it includes priceless period footage of the rocker’s innovative theatrics, complete with electric chairs and guillotines, boa constrictors and panties dropped from helicopters.

Come to think of it, maybe the movie’s comparatively conventional denouement makes a certain sense. After turning it up to 11 and letting it bleed, what was left for a millionaire shock-rocker to do but take up golf?

Also notable on VOD

Alejandro Jodorowsky, the surrealist filmmaker recently feted in the documentary “Jodorowsky’s Dune,” has released his first feature in 23 years, “The Dance of Reality,” which premiered last year in Cannes and opens Friday at the Uptown Theatre. Although the Chilean director’s monumental cult western “El Topo” (1970) isn’t yet available on demand, his grisly “Santa Sangre” (1989) can be rented or purchased in HD via Amazon, Vudu and Google Play.

What to say about a movie whose psychically damaged young protagonist becomes his mother’s arms? That it’s highly original? That it might just as well be called “Welcome to My Nightmare”? Perhaps it’s best to note simply that “Santa Sangre” is not for the squeamish — and that it’s highly recommended to those for whom Alice Cooper isn’t disturbing enough.